Phonograph



P 21, 1954 E. WENNERBO ETAL 2,689,734

PHONOGRAPH Filed April 2'7, 1951 2 Sheets-Sheet 1 FIG.

p 21, 1954 E. WENNERBO ETAL 2,689,734

PHONOGRAPH Filed April 27, 1951 2 Sheets-Sheet 2 FIG. 2

INVENTORS El-ck We finer-5o F 'L ZZ A, Jvensson BY W A ORNEW PatentedSept. 21, 1954 2,689,734 PHONOGRAPH Erik, Wennerbo, Motala, and FritzAugust Svensscn, Halmstad, Sweden, assignors to IndustriaktiebolagetLuxor, Mote-la, Sweden, a; Swedish joint-stock company Application,April 27, 1951, Serial Nbz- 223306 Claims priority, application SwedenMay 8, I950 3 Claims. 1

The present invention. relates to phonographs of the type provided withmeans for changing the rotational speed of the record carrying member(turntable) between a higher value (78 R. P. M.) for the playing or thehitherto usual records and at least one lower value (33 and 45 R. P. M.)for the playing of so-calledlong-playing records (LP records).

LP records require for their playing a needle or stylus whose shape isdifferent from that of the hitherto usualstylus, and therefore it isnecessary in phonographs for playing both, kinds of records to use twodifferent needles. The present invention provides for a simple andreliable means. in such phonographs for automatically bringing thecl'rect needle into workin position when therotational speed of therecord carrying member is changed.

In the phonograph according toour invention a sleeve is rotatablymounted in the pick-upcasing, a pin being yieldingly connected to saidsleeve at its one end and carrying at its other end two phonographneedles projecting substantially radially therefrom and at an anglerelatively to each other, of which needles one is a needle for playingstandard records and the other is a needle for playing LP records,amechanical connection permitting rotational movement of saidneedlecarrying pin being provided between the pin and the transducerunit of the pick-up for transmitting the needle vibrations to the latterunit, the speed changing means being connected to a mov able memberwhich is adapted to rotate the'sleeve together with the pin and thephonograph needlesupon actuation of said speed changing means so asautomatically to move the correct phonograph needle into theworkingpositi-on.

For the explanation of the invention reference is had to theaccompanying drawings which show a preferred embodiment of theinvention.

In Fig. 1 of the drawings, l designates a pickup casing. In the underside of this casing there is a rectangular recess 2 in the opposite endwalls of which the two ends 3 and of a sleeve-5 are rotatably mounted.The right hand end 4 of the sleeve engages a bore 9 in the casing l andcontains a helical spring 1 and a ball 8 which is forced against thebottom of the bore 9 by said spring, and. the left hand end 3 of the.sleeve is inserted from below into a groove l0 formed in the casing Iand is forced by the spring I axially against an abutment in said grooveso that the sleeve 5 will be retained in the pick-up casing in theposition shown. The sleeve 5 may readily be removed from the casing I bybeing displaced 2. to the right against the action of the spring Twhereupon the left hand end 3 is moved out of the groove Hi and finallythe right hand end 4 is pulled out of the bore: 9;

Into the left hand end of the sleeve 5 arubber stopper tl is. inserted.This stopper carries a pin i i substantially coinciding with the axis ofthe sleeve and? carrying at its free end: two radially extending needles13. and M, respectively, which form right angles with each other.

The pin t2 engages a fork-shaped end of a second pin [5 whichisconnected to a transducer unit it for converting mechanical vibrationsinto electrical impulses and comprising a piezo-electrical crystal, forinstance; The vibrations of the needle [3 (or M")- are thus transmittedto the transducer unit through the pins 12 and IS.

The middle portion 5 of the sleeve 5 is can tenedand twisted a quarterof a revolution, as shown. The twisted or helical portion 6 is adaptedto cooperate with the fork-shaped end of an arm H which, in turn, iscoupled to a control device for changing the rotational speed of therecord carrying member and which is moved longitudinally relatively tothe sleeve 5 when the said control device is actuated, thereby rotatingthe sleeve 5 through a quarter of a revolution between its two endpositions. If the needle 5 3 which is shown in the working position inthe drawing is a needle for playing standard records (recorded at aspeed of 7-8 R. P. M.) and the needle M is one for playing LP records,changing the rotational speed from 78 R; P. M. to 33 or R. Pi M will?cause the arm I? to be moved to the. left whereby the sleeve 5 will berotated anti-clockwise (as viewed from the left hand end 3* of thesleeve) and the needle id for LP records will be moved down into theworking position.

Figure 2 shows the entire arm [1, one end of which is fork-shaped forengaging the helical portion 6 whereas the other end of the arm forms ahandle 18. The arm I! has a cam surface I!) engaging a pin 26 which iscarried by an arm 22 on the phonograph motor 2!. The motor 2| has ashaft 23 which in the position shown in the figure engages anintermediate wheel 24 which, in turn, engages an inner flange 26 on theturntable, said flange being concentric with the turntable shaft 27. Theturntable has also an outer concentric flange 28. In the position of thevarious details shown in the figure the motor shaft 23 rotates theintermediate wheel 24 which engages the flange 25 and rotates theturntable at a speed of '78 R. P. M. If the arm I! is displaced upwardsin the direction of the arrow the pin 20 actuates 3 the cam surface I9and moves the arm 22 and the motor 2| to the left so that the motorshaft 23 engages the outer flange 28 and thus rotates the turntable at aspeed of 33 /3 R. P. M.

Modifications of the device as described above are conceivable withinthe scope of the appended claims.

ing substantially radially therefrom and at an angle relatively to eachother, one of said needles being a needle for playing standard recordsand the other being a needle for playing LP records, a transducer unitmounted in the pick-up casing, a mechanical connection permittingrelative rotational movement provided between said needle-carrying pinand said transducer unit for transmitting the needle vibrations to thelatter, a substantially linearly movable member connected to said speedchanging means and adapted to cooperate with the helical guide means ofthe sleeve for automatically rotating said sleeve upon actuation of thespeed changing means for moving the correct needle into the workingposition, the sleeve being rotatably mounted in the pick-up casing atits ends, an intermediate portion of the sleeve being flattened andtwisted helically, and said helical portion being adapted to cooperatewith the fork-shaped end of an arm which is connected to the speedchanging means and is adapted to be moved thereby in the longitudinaldirection of the sleeve upon actuation of said speed changing means forchangin the rotational speed of the record carrying member.

2. In a phonograph provided with means for changing the rotational speedof the record carrying member between a higher value for the playing ofstandard records and at least one lower value for the playing of LPrecords, a tone arm, a transducer casing in said tone arm, said casingbeing kept against rotation around the length axis of the tone arm, asleeve rotatably mounted in said casing, a pin yieldingly connected tosaid sleeve at its one end and carrying at its other end two phonographneedles projecting substantially radially therefrom and at an anglerelatively to each other, of which needles one is a needle for playingstandard records and the other is a needle for playing LP records, atransducer unit mounted in the transducer casing, a coupling membersecured to said transducer, a recess in the free end of said couplingmember, an integral portion of said pin rotatably engaging said recessand mechanical means connecting said sleeve with said speed changingmeans for automatically rotating said needle-carrying pin upon actuationof the speed changing means so as to move the correct needle into theworking position.

3. In a phonograph provided with means for changing the rotational speedof the record carrying member between a higher value for the playing ofstandard records and at least one lower value for the playing of LPrecords, a tone arm, a transducer casing in said tone arm, said casingbeing kept against rotation around the length axis of the tone arm, asleeve rotatably mounted in said casing said sleeve having anintermediate portion flattened and twisted helically, a pin yieldinglyconnected to said sleeve at its one end and carrying at its other endtwo phonograph needles projecting substantially radially therefrom andat an angle relatively to each other, of which needles one is a needlefor playing standard records and the other is a needle for playing LPrecords, a transducer unit mounted in the transducer casing, a couplinmember secured to said transducer, a recess in the free end of saidcoupling member, an integral portion of said pin rotatably engaging saidrecess and mechanical means connecting said sleeve with said speedchanging means, said means comprising a substantially linearly movablemember having a forkshaped end cooperating with said helical portion ofthe sleeve and adapted to be moved in the longitudinal direction of thesleeve for automatically rotating said sleeve for bringin the correctneedle into the working position upon actuation of said speed changingmeans for changing the rotational speed of the record carryin member.

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